CareerBuilder spokesman Michael Erwin says each of those companies is posting hundreds of job openings.

“What we have seen on our site is a 20 percent increase in the number of jobs that are posted, and what companies are telling us are, they’re still cautious, but they are adding jobs, and these companies are definitely proof that there are jobs out there,” Erwin said.

CareerBuilder says several companies, including Aon, are looking for 1,000 or more employees.